The art of inkjet printing is relatively well known. In general, an image is produced by emitting ink drops from a printhead at precise moments such that they impact a print medium at a desired location. The printhead is supported by a movable print carriage within a device, such as an inkjet printer, and is caused to reciprocate relative to an advancing print medium and emit ink drops at times pursuant to commands of a microprocessor or other controller. The timing of the ink drop emissions corresponds to a pattern of pixels of the image being printed. Other than printers, familiar devices incorporating inkjet technology include fax machines, all-in-ones, photo printers, and graphics plotters, to name a few.
A conventional thermal inkjet printhead includes access to a local or remote supply of color or mono ink, a heater chip, a nozzle or orifice plate attached or formed with the heater chip, and an input/output connector, such as a tape automated bond (TAB) circuit, for electrically connecting the heater chip to the printer during use. The heater chip, in turn, typically includes a plurality of thin film resistors or heater elements fabricated by deposition, masking and etching techniques on a substrate such as silicon.
To print or emit a single drop of ink, an individual heater is uniquely addressed with a predetermined amount of current to rapidly heat a small volume of ink. This causes the ink to vaporize in a local bubble chamber (between the heater and nozzle plate) and be ejected through the nozzle plate towards the print medium.
Typically, nozzle plates that attach to the heater chip, post-chip-formation, have certain economic and mechanical drawbacks relating to the alignment between the nozzle plate orifices and the heater elements. As is known, poor alignment causes product defects or ineffectiveness. On the other hand, nozzle plates concurrently formed with the heater chip often suffer deformations in ink flow features or nozzle orifice shapes upon subsequent chip processing steps. Again, product defects or ineffectiveness can result. In addition, concurrently formed nozzle plates often require multiple solvent dissolving/removal steps which add cost and complexity to the fabrication sequence.
Accordingly, a need exists in the nozzle plate art for economic and simple designs that overcome misalignment and malformation and require minimal processing steps.